The proportion of U.S. children and adolescents on psychiatric medications more than doubled from the mid-1980s to the mid-1990s -- a trend that could either signal alarming overuse or evidence that more kids who need treatment are finally getting it, doctors say.

A study published today reports that the percentage of kids on drugs for such diagnoses as anxiety, depression, attention deficit hyperactivity disorder and bipolar disorder rose to 6 percent in a population of 900,000 young patients between 1987 and 1996.

The study's authors said their findings indicate that the percentage of children on psychiatric drugs is now about on par with adults.

The data came from patients age 19 and younger who were enrolled in different parts of the country in two Medicaid programs and in a Kaiser Permanente HMO. The findings were published in the Archives of Pediatrics and Adolescent Medicine.

Psychiatric drug use tripled in the HMO patients in the Northwest and in those in a Medicaid program in the Midwest. It doubled in the second Medicaid program, in a mid-Atlantic state. Other studies suggest the trend has continued since 1996.

Dr. Glen Elliott, director of the Children's Center at Langley Porter, the mental health unit at UCSF for children, said little is known about the long- term effects on children from taking psychiatric drugs.

"It's truly a profound change in the way we go about doing medicine, but whether that's better or worse for the way we treat children and adolescents, we're not sure yet," said Elliott, who was not affiliated with the study.

SEDATING EFFECTS

Stimulants, such as Ritalin for attention deficit disorder, were the most commonly prescribed psychiatric drug in 1996, the last year of data used in the study. There were also increases in the use of antidepressants and mood stabilizers such as valproic acid and gabapentin, which were originally used to control seizures.

A particularly large increase over time was seen in the number of kids on alpha-agonist drugs, which were developed to treat high blood pressure in adults.

Doctors are using them in kids with ADHD because its sedating side effects seem to help them sleep, according to Julie Magno Zito, associate professor of pharmacy and medicine at the University of Maryland and lead author of the study.

"In some cases they're exploiting the side effects of the medications -- it knocks the fight out of you," Zito said. "But what are the risks and benefits? What is it doing to their cardiovascular system? We don't know."

Elliott agreed, saying there are virtually no studies to indicate alpha- agonists are a good idea, but they are being widely used anyway. In Zito's study, the largest increase in usage was among children enrolled in Medicaid, the federal health care program for the poor.

But Elliott said the overall trend may actually prove heartening. For one thing, drugs have gotten more effective and much safer, and more parents are willing to seek help for their child.

In earlier years, "the assumption was that it's your fault -- you're a bad parent or you have a bad kid, or both," Elliott said. "Nobody could do anything for you anyway, so why bother?"

LACK OF INFORMATION

According to Dr. Michael Jellinek, chief of child psychiatry at Massachusetts General Hospital, Zito's findings might be cause for optimism if they reflect better diagnoses, less reliance on talk therapy exclusively, and effective use of the medications.

But Jellinek said the lack of information about exactly how the drugs are being used makes getting that answer difficult. Unlike efforts to track the treatments provided to people with chronic medical illnesses, health insurers are not tracking or making available data on psychiatric medications.

"We're very careful about how we are taking care of patients with diabetes and heart disease, to make sure they're getting the right medicines, the right interventions," Jellinek said.

"In the databases (of large insurance companies), we could look at which kids are getting which medications, who prescribed it, whether they had access to therapy. But the companies that control the managed care of these children aren't very forthcoming."